L &amp; N cycle for hydrogen, electricity, &amp; desalinated seawater

ABSTRACT

The L &amp; N Cyde combines a single heat source with several different cycles into one unique system that takes maximum advantage of the heat available. The cycles/systems included are 1) a chemo-thermal process to convert water into oxygen and hydrogen, 2) a modified Regenerative Brayton cycle to produce electricity, 3) a thermal flash distillation desalination cycle 4) a reverse osmosis desalination cycle, and 5) ion-exchange mineral extraction system. The heat source will supply a temperature of about 900° C. to 1,000° C. to the chemo-thermal furnace for that process. The hot products of the chemo-thermal water conversion process (oxygen and hydrogen) pass through different heat exchangers to supply heat to the other cycles. In this manner the oxygen and hydrogen proceed through their first cooling step. The hot hydrogen heat exchanger supplies heat to the fluid in the Regenerative Brayton cycle to produce the electricity. The hot oxygen heat exchanger supplies the heat to convert the seawater to steam to extract the salt. The L &amp; N Cycle provides the United States with the economics to allow the success of a hydrogen economy, provide independence from foreign oil, and advert our electricity and fresh water crisis.

STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT

[0001] The Federal government did not directly sponsor any research ordevelopment for the invention of the L & N Cycle. However, most of theelements of the L & N Cycle have had research or development sponsoredby different agencies of the Federal Government. The L & N Cycle utilityinvention combines a single nuclear and/or solar heat source with suiteof integrated state-of-the-art processes for production of hydrogen,electricity, oxygen, salt, extractible minerals, low grade process heat(warm brine at −100 degrees F.) and desalinated seawater in a manner notconsidered in past designs. Hence, the invention significantly reducesthe cost of producing hydrogen, electricity, and desalinated seawater.

BACKGROUND OF THE INVENTION

[0002] Our country is facing three separate crisis situations with oil,power, and water resources. The current electrical power crisis inCalifornia has stirred interest in new ways to produce and distributeelectricity. Solar power is a clean method to produce electricity butindependently it cannot compete with natural gas and coal power plants.Nuclear reactor power plants can compete with natural gas and coal, butif the cost of disposing nuclear waste is included, they may not becompetitive. The L & N Cycle will improve economics of these processesand aid in reducing dependence on natural gas.

[0003] Moving in the direction of a hydrogen economy will reduce ourdependence on foreign oil. Hydrogen is required by 1) the oil industryto improve extraction of clean gasoline from heavy crude oil, 2) theautomobile industry for fuel cells, 3) making fertilizer, and 4) manychemical processes. Oil refineries use hydrogen to make gasoline. Crudeoil requires hydrogen to refine it into gasoline. Using very heavy crudeoil with more hydrogen can provide clean gasoline. Low cost non-fossilhydrogen will also reduce the price of gasoline to the public. Today themajority of hydrogen is produced from natural gas, and therefore isdependent on natural gas prices. Since a majority of the electricalpower plants in California use natural gas, their electrical powercrisis caused a significant increase in natural gas prices and hence anincrease in the cost of hydrogen. The higher cost of hydrogen was passedon to the public through higher gasoline prices. Developing a non-fossilmethod to produce hydrogen will reduce our dependence on foreign oil andgas. The L & N Cycle will improve the economics of these processes andaid in reducing dependence on foreign oil and natural gas.

[0004] Our country is also facing a fresh water crisis. Texas waterconservationists predict that Texas will run out of fresh water in 10years. California is already in a water conservation mode. Thepopulation of California is predicted to double in the next 50 years andwill need an alternate source for water. Just as the renewableelectrical power and non-fossil hydrogen production processesindependently are expensive, so is desalination of water. If we candevise an economical method to desalinate seawater we could advert thefresh water crisis. The L & N Cycle will improve the economics ofdesalination of seawater.

[0005] The L & N Cycle has application in our hydrogen economy,electricity crisis and fresh water crisis. Combining a chemo-thermalhydrogen production cycle, an electric power production cycle and awater desalination cycle into one system, sharing one heat source, willprovide the economics to allow each product to be competitive in theirrespective markets. The L & N Cycle will allow recovery of the upfrontcapital required for implementation and the plant operating cost fromthree different industries oil, Power, and Water. This patentapplication is for the unique integration of several independent cyclesinto one system that maximizes the use of the thermal capability from asingle heat source. The L & N Cycle is independent of the heat source.

BRIEF SUMMARY OF THE INVENTION

[0006] The L & N Cycle is a system that will produce hydrogen, generateelectricity, provide process heat and steam, support mineral extractionvia ion-exchange, desalinate seawater via reverse osmosis and/or flashdistillation and produce warm brine appropriate for use in domesticheating and cooling using a single heat source coupled to an integratedthermal power/pump cycle. The L & N Cycle combines several differentcycles into one unique system that takes maximum advantage of the heatavailable. The cycles/systems included are 1) a chemo-thermal process toconvert water into oxygen and hydrogen, 2) a modified RegenerativeBrayton cycle, 3) a thermal flash distillation desalination cycle 4) areverse osmosis desalination cycle, and 5) ion-exchange mineralextraction system. The heat source will supply a temperature of about900° C. to 1,000° C. to the chemo-thermal furnace for that process. Thehot products of the chemo-thermal water conversion process (oxygen andhydrogen) pass through different heat exchangers to supply heat to theother cycles. In this manner the oxygen and hydrogen proceed throughtheir first cooling step. The hot hydrogen heat exchanger supplies heatto the fluid in the Regenerative Brayton cycle to produce theelectricity. The hot oxygen heat exchanger supplies the heat to convertthe seawater to steam to extract the salt.

DETAILED DESCRIPTION OF THE INVENTION

[0007] The L & N Cycle combines multiple state-of-the-art cycles toemploy one heat source. The first cycle will produce hydrogen and oxygenfrom a chemo-thermal reaction. There are a few different chemo-thermalprocesses to produce hydrogen. A 600 MWt heat source heats thechemo-thermal furnace to about 900° C. to 1000°C. Water and variouschemicals are introduced resulting in oxygen and hydrogen. At this pointhydrogen would be cooled and transferred into the current hydrogenpipelines. The University of California, Texas A & M, and others aredeveloping this process. Instead of going directly to the hydrogenpipeline, the L & N Cycle would divert the hot hydrogen to pass througha heat exchanger to transfer its heat to the fluid in a Brayton orRegenerative cycle to produce electricity. The hydrogen would exit theheat exchanger cooled to the entering temperature of the Brayton orRegenerative cycle fluid. The hydrogen would then pass to the hydrogenpipelines. The heat source for the modified Brayton or Regenerativecycle is derived from the above heat exchanger. The electrical powercycle can be an open loop or closed loop cycle. The attached drawingillustrates the L & N Cycle with a closed loop Brayton cycle using aninert gas such as helium in the turbo-compressor. A thermal balance willdetermine the use of a modified Brayton cycle or a Regenerative cycle.The cycle consists of a turbo-compressor, alternator, and a heatexchanger. With a 600 MWt heat source for the chemo-thermal process, thehydrogen will have a high enough temperature to heat the fluid in theturbo-compressor cycle. With an overall efficiency of 25% the systemcould produce 150 MWe of electricity. The electrical power cycle heatexchanger would use seawater as the cooling agent. The seawater willexit the electric power cycle heat exchanger in five forms. These wouldbe desalinated steam, which will be sent through a condenser to yielddesalinated water, warm brine, warm desalinated (reverse osmosis) water,salt, and extractable minerals (ionexchange) such as uranium, manganese,and gold.

[0008] Another product of the chemo-thermal process is very hot oxygen.The L & N Cycle proposes to use the hot oxygen to pass through a secondheat exchanger to transfer heat to seawater to turn the seawater intosteam to remove the salt. The steam would pass into a container to bemixed/sprayed with the oxygen exiting the heat exchanger forpurification. The mixture would then proceed to a condenser to yieldwater. The L & N cycle uses heat normally wasted from the chemo-thermoprocess for cycles that can produce electrical power and desalinatedwater.

1. The L & N cycle files a claim as a system that applies a single heatsource to state-of-the-art processes to produce a) hydrogen and oxygenfrom water through a chemo-thermal reaction, b) electricity with amodified regenerative brayton cycle, c) desalinate seawater through athermal flash distillation desalination cycle and/or a reverse osmosisdesalination cycle, and d) ion-exchange mineral extraction system. 2.The L & N Cycle files a claim as a system that applies a single heatsource to state-of-the-art processes to produce a) hydrogen and oxygenfrom water through a chemo-thermal reaction and b) electricity with amodified Regenerative Brayton cycle.
 3. The L & N Cycle files a claim asa system that applies a single heat source to state-of-the-art processesto produce a) hydrogen and oxygen from water through a chemo-thermalreaction, b) desalinate seawater through a thermal flash distillationdesalination cycle and/or reverse osmosis desalination cycle, and c)ion-exchange mineral extraction system.